Lithium-ion battery and electrolyte thereof

Abstract

The invention discloses a lithium-ion battery and an electrolyte thereof. The electrolyte comprises a non-aqueous organic solvent, lithium salt and additives, wherein the non-aqueous organic solvent contains a methyl ester compound A; the additives comprise an additive B--a silicon oxysulfide compound and an additive C which is at least one selected from the group consisting of an ether bond containing lithium disulfonate compound and an ether bond containing lithium disulfate compound; and the silicon oxysulfide compound is at least one selected from the group consisting of compounds as shownin a formula (I) which is described in the specification. Compared with the prior art, the lithium-ion battery and an electrolyte thereof provided by the invention have the following advantages: through synergistic effect of the methyl ester compound A, the additive B and the additive C, overcharge resistance and cycle performance of the lithium-ion battery can be improved, and the safety performance of the battery is improved.

Description

technical field [0001] The invention belongs to the field of batteries, and more specifically, the invention relates to a lithium ion battery and an electrolyte thereof. Background technique [0002] Lithium-ion batteries have the characteristics of high energy density, high power density, good cycle performance, no memory effect, and environmental protection. Therefore, they are widely used in mobile communication equipment such as mobile phones, mobile cameras, notebook computers, mobile phones and other electronic products. At the same time, it has also become a strong candidate for the energy supply system of electric vehicles in the future. [0003] At present, the safety of lithium battery electrolyte has become one of the biggest obstacles to the commercialization of large lithium-ion batteries. Explosion, fire and other dangers are caused by overcharging of lithium-ion batteries. In order to solve these safety problems, the traditional method is to install a gas pre...

AI Technical Summary

Problems solved by technology

The traditional method not only increases the cost and complexity of the battery, but also has unsatisfactory safety effects

[0004] In the prior art, additives have been used to solve the problem of battery internal overcharge protection, but the existing additives are basically limited to biphenyl, cyclohexylbenzene, etc. and their derivatives. These additives can play a certain role in battery safety, but It will affect the normal electrochemical performance of the battery, especially the charge and discharge performance and cycle performance. At the same time, it will generate a large amount of gas during the charge and discharge process, resulting in a decline in battery performance.

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